The first hour or so was simply roleplay as the players got their quest and tooled themselves up for the adventure ahead. This all went down really well, the lack of a complete skills list was a little alien at first, meaning we simply used the appropriate attribute to modify a check. There were only a few disputes over which attribute should be used and generally it played smoother than having a full skills list since the players were less inclined to constantly refer to their skills to determine what they could do.
For combat we choose to do away with the grid that we had become so accustomed to in 4E. This wasn't an entirely new concept as we had played Tunnels and Trolls many times before. Everyone seemed to enjoy the more imaginative combat, feeling it flowed more smoothly. It got a little hectic as large groups of monsters were introduced but we never got bogged down. combat was also much quicker than in 4E, something that we were all thankful for. In the 5 hours of play we had maybe 6 encounters plus a whole lot of roleplay, a big improvement over 4E.
The advantage and disadvantage system was liked by all. It is a much more elegant solution than having a bunch of +/-2's to keep track of. Though advantage seemed to happen a lot for both the players and the monsters with disadvantage being much less frequent. It wasn't much of a problem but its something I will address next time we play.
The reduction to each turn being movement and an action actually allowed the players more freedom to act. In 4E the restriction put on the players by the different type of actions didn't really allow for much outside the box thinking. You would just pick a power, move into position and use it. Now though, since 'action' is so vague it gives the players much more scope to do kickass things each round.
The PC's themselves were pretty awesome. We had the Wizard, the Rogue and the Battle Cleric, each of which definitely captured the essence of that class well. The biggest problem we came across was with the Wizard. The players were fighting a lot of Kobolds to begin with and his Magic Missle was auto killing them each round since its minimum damage was higher than the Kobolds HP and with its auto hit the Wizard was getting pretty bored since he wasn't rolling anything. Of course this changed once they fought things with higher HP and the cantrips were a very nice addition, allowing the Wizard to still act after he had used sleep and burning hands to great effect.
Everyone especially liked the introduction of Hit Dice. They worked much better than healing surges, we all agreed that limited healing made each battle much more intense. Which of course led to us having a problem with healing up fully after an extended rest, something that even Mike Mearls has apparently errata'd on Twitter.
Over all we had a great time and I will most likely have some more thoughts on the new edition this weekend after we play again.